In the prior art a hand held mobile telephone generally comprised: a front face having a longitudinal extension greater than a lateral extension and having a plurality of openings therein; and a multiplicity of keys each having an upper surface bounded by side walls, wherein each key protrudes from one of the plurality of openings to provide its upper surface for tactile actuation by a user wherein a plurality of said multiplicity of keys are arranged along a common first axis, in the longitudinal direction. Typically a phone would have a 3 by 4 array (4 lateral rows and 3 longitudinal columns) of identical keys arranged for alphanumeric input.